The purpose of this proposal is to obtain financial support for the 2nd American-ISS Course in Stereology which will be held in Florida, April 25-May 2, 1987. The specific aim of this workshop is to teach young investigators in the medical sciences in the United States and Canada the basic principles in stereology and to provide them with knowledge of the new developments in this field. A group of leading scientists in the field of stereology will present a seven-day intensive course sponsored by the International Society for Stereology (ISS). The course is designed especially for biologists working with morphologic techniques such as light and electron microscopy. Support of this workshop by the National Institutes of Health is important, not only for the young investigators who have limited funds, but also for the future of stereology and its biological application in this country. The requested money will be used to pay the travel of speakers from Europe to Gainesville, Florida, and to cover expenses for printing and mailing of programs and lecture notes. No salary monies or honorarium will be paid to any of the speakers.